Over the past century, IQ scores in the United States have shown a significant increase. According to a phenomenon known as the “Flynn effect,” IQ scores have been increasing by around three to five points per decade. However, a recent study by Northwestern University found evidence of a reverse Flynn effect in a large U.S. sample between 2006 and 2018. The study showed negative slopes for three out of four cognitive domains, including verbal reasoning, matrix reasoning, and letter and number series scores.
Despite the decline in scores, the study’s corresponding author Elizabeth Dworak, a research assistant professor of medical social sciences at Northwestern University, cautioned against assuming that Americans are getting less intelligent. Dworak suggested that the decline in scores could be due to changes in test-taking ability or changes in values and motivations in society.
A shift in perceived values in society might have affected scores as well. If we think about what society cares about and what it’s emphasizing and reinforcing every day, there is a possibility that it is reflected in performance on an ability test. For instance, there has been more emphasis on STEM education in recent decades, but does that mean other areas, like abstract reasoning, are receiving less attention in schools?
Another factor could be due to a decline in motivation. Because the SAPA Project is advertised as a personality survey, individuals seeking out the test may be more engaged with sections related to measuring temperament and less engaged with sections that are seemingly unrelated to personality.
